All my Grumichama fruits have the remains of the flower attached to the non-stem end. Doesn't look like they removed them for a prettier picture, so guessing not grumichama fruits.
there's only two explanations, both of which are unfavorable...
1) they don't know the difference between Garcinia fruits, and Eugenia fruits.
or
2) lacking an example of an actual yellow Grumichama, they made a cheeky attempt to pass off a fruit that superficially looks similar, known as Garcinia brasiliensis "Lemon Drop Mangosteen".
lol they even included a stem from the Garcinia in the photo....which of course doesn't have bark that exfoliates like Grumichama.